Created attachment 197671 [details]
The BROKEN_powerpc64 message was incorrect - the problem was not "-Wno-logical-op-parentheses" flag, but a linking issue.
That's why USES=compiler:c11 is necessary. With it, this port builds on powerpc64.
Tested also on amd64.
Hardware sponsored by IntegriCloud.
A commit references this bug:
Date: Mon Oct 1 17:18:19 UTC 2018
New revision: 481042
Require a modern compiler to fix build on powerpc64